Math Problem Statement

Two vectors are given by a = (4.0 m)i - (3.0 m)j + (1.0 m)k and b = (-1.0 m)i + (1.0 m)j + (4.0 m)k. In unit-vector notation, find (a) a + b, (b) a - b, and (c) a third vector c such that a - b + c = 0.

Solution

Let’s solve the problems presented in Question 9 step by step. Here's the detailed breakdown:


Problem 9

Two vectors are given:
a=(4.0m)i^(3.0m)j^+(1.0m)k^\vec{a} = (4.0 \, \text{m})\hat{i} - (3.0 \, \text{m})\hat{j} + (1.0 \, \text{m})\hat{k}
b=(1.0m)i^+(1.0m)j^+(4.0m)k^.\vec{b} = (-1.0 \, \text{m})\hat{i} + (1.0 \, \text{m})\hat{j} + (4.0 \, \text{m})\hat{k}.

You are tasked to find:
(a) a+b\vec{a} + \vec{b},
(b) ab\vec{a} - \vec{b}, and
(c) a vector c\vec{c} such that ab+c=0\vec{a} - \vec{b} + \vec{c} = 0.


(a) Find a+b\vec{a} + \vec{b}:

To add two vectors, sum their corresponding components.
[ \vec{a} + \vec{b} = [(4.0 + (-1.0))\hat{i}] + [(-3.0 + 1.0)\hat{j}] + [(1.0 + 4.0)\hat{k}] ]

Simplify:
a+b=(3.0m)i^(2.0m)j^+(5.0m)k^.\vec{a} + \vec{b} = (3.0 \, \text{m})\hat{i} - (2.0 \, \text{m})\hat{j} + (5.0 \, \text{m})\hat{k}.


(b) Find ab\vec{a} - \vec{b}:

To subtract two vectors, subtract their corresponding components.
[ \vec{a} - \vec{b} = [(4.0 - (-1.0))\hat{i}] + [(-3.0 - 1.0)\hat{j}] + [(1.0 - 4.0)\hat{k}] ]

Simplify:
ab=(5.0m)i^(4.0m)j^(3.0m)k^.\vec{a} - \vec{b} = (5.0 \, \text{m})\hat{i} - (4.0 \, \text{m})\hat{j} - (3.0 \, \text{m})\hat{k}.


(c) Find c\vec{c} such that ab+c=0\vec{a} - \vec{b} + \vec{c} = 0:

Rearranging for c\vec{c}:
c=(ab).\vec{c} = -(\vec{a} - \vec{b}).

From part (b), we know:
ab=(5.0m)i^(4.0m)j^(3.0m)k^.\vec{a} - \vec{b} = (5.0 \, \text{m})\hat{i} - (4.0 \, \text{m})\hat{j} - (3.0 \, \text{m})\hat{k}.

Negating each component:
c=(5.0i^4.0j^3.0k^)=(5.0m)i^+(4.0m)j^+(3.0m)k^.\vec{c} = -(5.0 \, \hat{i} - 4.0 \, \hat{j} - 3.0 \, \hat{k}) = (-5.0 \, \text{m})\hat{i} + (4.0 \, \text{m})\hat{j} + (3.0 \, \text{m})\hat{k}.


Final Answers:

  1. (a) a+b=(3.0m)i^(2.0m)j^+(5.0m)k^\vec{a} + \vec{b} = (3.0 \, \text{m})\hat{i} - (2.0 \, \text{m})\hat{j} + (5.0 \, \text{m})\hat{k},
  2. (b) ab=(5.0m)i^(4.0m)j^(3.0m)k^\vec{a} - \vec{b} = (5.0 \, \text{m})\hat{i} - (4.0 \, \text{m})\hat{j} - (3.0 \, \text{m})\hat{k},
  3. (c) c=(5.0m)i^+(4.0m)j^+(3.0m)k^\vec{c} = (-5.0 \, \text{m})\hat{i} + (4.0 \, \text{m})\hat{j} + (3.0 \, \text{m})\hat{k}.

Would you like me to solve Question 10 or 11 next? Let me know!

Related Questions:

  1. How do you calculate the magnitude of a vector given its components?
  2. How do you subtract vectors graphically and analytically?
  3. What is the resultant of multiple vectors in unit-vector notation?
  4. How can you determine a vector that balances a given vector equation?
  5. How do you express vectors in different coordinate systems?

Tip: Always add or subtract vectors component-wise: sum or subtract the coefficients of i^\hat{i}, j^\hat{j}, and k^\hat{k} separately.

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Math Problem Analysis

Mathematical Concepts

Vector Addition
Vector Subtraction
Vector Components

Formulas

Vector Addition: a + b = (a_x + b_x)i + (a_y + b_y)j + (a_z + b_z)k
Vector Subtraction: a - b = (a_x - b_x)i + (a_y - b_y)j + (a_z - b_z)k
Balancing Vectors: c = -(a - b)

Theorems

Vector Component Theorem

Suitable Grade Level

Grade 10-12 (High School Physics/Math)